Ben1098

I bought an almost NEW swimmer....drunk fishing buds went to river....to not get a DWI....left MASSY at river....best part....left keys in the ignition....river sandbar recovery. Hoped for best with this pig in a poke. Sanded piston/cyl. Crank bearings "rough". Even the transmission bearings had multiple bind spots. New oil pump. Still money ahead. The rear output shaft was leaking BEFORE the swim by the oil slick on present.....BTW, watch this very close....sealant gets hard and leaks not at the seal BUT thru the spline...NICE. That was 4 years ago....keep the oil level up and CLEAN and watch for air lock in coolant. Special bleed procedure...FRONT RAISED about a foot...makes radiator higher than engine head bleed screw. The Al tubes that run in the bottom floor pan HAVE TO HEAT UP WHEN WARMING UP MOTOR....this means the coolant is flowing to the radiator. BTW, it is a YAMAHA RHINO clone with motor parts interchangeable......I suspect the cam with it's compression release was made by the same SUB......I worked on BOTH units that the weld assy step was WRONG EXACTLY IDENTICAL.....so my spare cam (modified/fixed) went into a RHINO. My experience......they all have problems (repeat problems)...worst is hillside + idle oil failure (crispy head). Back to RHINO/HISUN (these motors are in everything....big box). Common failure in R, Hisun fixed with a more robust bearing so these parts are not interchangeable. Electrical problems...don't go there. Ho would not start while cranking....will catch when starter is released. Even a "solid" design will fail when the starter hot cable is bundled with the pickup coil signal wires.....same as a RAM with the alt cable trashing the ECM inputs. Gotta go.

The seat rear has 3 molded plastic "fingers" that go under the 8mm rod bent/formed to make a "receiver" to hold the rear of the seat. Past problems were the rod was deformed (motor drop in????)....just straighten back out to gain the req'd clearance. Once the bent rod receiver was "off location" rubbed on the side instead of the top. This fix uses a flap wheel to GENTLY trim the offending plastic finger. If still not finding the problem, measure the 3 finger L-R locations....compare to the welded receiver rod openings. Further, measure the top-bottom thickness and make a stack of pop sickle sticks (or whittle from a lathe) us use as a plug gauge. As far as the FRONT latch pin not working......look into the front pin hole. See the 4 mm spring sitting crossways that moves with the seat latch lever. Released, the 4mm spring (the section you can see) will extend about 8mm or so into the molded hole.....latch pulled, the 4mm spring is retracted past the hole diameter. This 4mm spring is what snags on the pin (sticking up from the body) with the annular machined 5mm groove. Past problems here.........plastic latch lever spring grabbing projection GONE as in broken off. NO spring movement or not full travel. Next, the seat will go on BUT not latch...even with a little bap on the seat front. Problem is the latch assy cannot drop deep enough on the pin to get captured by the 5mm annular groove. SHIM the latch to make it "lower" i.e. remove screws, make a plastic shim (liquid laundry soap jug) with screw holes and try again. Last, pin was hit (engine drop in???) and have an obvious banana look......extra...dry or binding 4mm spring is "smashed between the seat latch halves. Careful round file trimming req'd here. CHOW

Find the Delphi ECM. Should have 2 connectors----gray and black. There are two +12vdc inputs. One (pin 18) is ALWAYS HOT (like memory on radio) and then the other(pin 15) is hot only with KEY ON. Don't have ECM pin out handy so I can't state which color connector. With KEY OFF, remove both connectors (identical except color) and find the fine print molded pin numbers. KEY ON. Needle probe (don't stab and ruin the terminal) the pin(s) number looking for the 2 +12v inputs. After finding, KEY OFF to see if pin 15 goes away (check to see if you are in the right track). Problems found in past....fuse blown, smashed connector, mouse house chews, and loose connector. There is not a good wiring diagram. The same DELPHI ECM module (retuned) is on late B & S FI V-Twin lawn mower engines and the pinout can be found with YAHOO search using DELPHI ECM PINOUT. Without the two supply pins, the ECM plays dead....check before spending $$$$$$$$$$$$$$$$$. CHOW

Travis.....just read starter tale of woe. The 2nd starter (CHINO) had an internal open circuit i.e. the brushes or armature. Older starters did not have stopper brush holders, and as the brushes wore down (and spring tension less), the Cu braid cable would burn a trench in the commutator Cu bars....no fix except to have the armature rebuilt. Newer starter brush plates have the stopper and then after wearing down to where the brushes Cu braided wire hit the stopper bar, end up having a poor contact connection....new (full length) brushes, clean armature, and good to go. Tapping will "fix" in early stages to get you back home. Another problem is holding the key on and the motor not turning....will generate a hot spot and lift the Cu bar. Another problem is the edges of the Cu bars will burn away leaving a "rounded" not flat bar.....since the brushes cannot hit a 'full' bar width, current is less....fix is to turn down commutator bars on lathe...within reason...for a second chance before the scrap barrel. Explaining your test: You had the same voltage on the battery terminal AND the starter motor hot terminal...case is GND. The battery cable has resistance so expect a small drop say .4 to .6 v drop. The solenoid contacts (big ums) are about 0 v if good. NO CURRENT FLOW. Current flows from HOT terminal in to a brush (2 brush plate) or opposite brushes (4 brush plate)-----thru commutator Cu bars.....thru Cu armature windings----back to the CU bars...then out the single or dual brushes to case--- GND. What to look for from past T/S findings. Brushes worn.....too short or light pressure. Weak springs. Spring hung on brush holder..as in placed not on the slot on the back side of brush. Spring holder "box" not square....like something hit it at assy or stepped on...makes the brush bind. Mechanical........worn small bushing or dry big end bearing making it hang then burn the Cu bar. You might be able to save the chino....but don't expect a rebuild kit to fit. RICK'S was our vendor of choice a few years back. He had stators, regulators, CDI, etc. don't know if he is still in business. Pricing on OEM parts. 80 and 90's 100% markup........COST $60 MSRP $120. Then dollar/yen hit, COST $80 MSRP $120. That was how the pricing line was held......There are tons of OEM parts out there from Dealers inventory auctions/liquidations who went belly up. Some sellers pass on a good deal while others are greedy.

DIFF problem....you will have 2 connectors...one to switch power + to - and - to +......this runs the small electric DC motor that slides the rack (behind/under the black round shift servo) from left to right to left. There are 3 positions.....2 WD, "3 WD" which is an open diff where if front end is lifted, the wheels rotate in opposite directions (with drive shaft locked) and then 4WD which locks BOTH fronts together. Someone in the past has shifted into 4WD UNDER LOAD (and moving)....SNAP CRACKLE POP with emphasis on the POP. DO the rack test (remove the black shift module....bolts here.....and slide the rack L to R to L. Be aware that the position of the rack has to be "timed" to the servo unit. Write down the dash switch(s) position (I like 3 WD) AND where exactly where the rack is sitting (in the middle slightly off center for 3 WD). Test the servo by having another person run the buttons and you look for the gear to turn and motor to buzz. The gear will go CCW and CW and CCW...exactly the way the rack should slide back and forth to select the desired function. If the rack slides with no resistance from side to side...internal busted push pin on rack. If working, the rack will move slightly and then stop because you have to rotate the wheels (spin the diff) to align the diff gears and then finish the "shift" The servo has a "wind-up" spring between the electric motor drive and the gear output that "winds up". What this does is put pressure (like you are doing with your hand) on the rack waiting for the gears to align. There are contact tracks/Cu brushes (limit switches) that rotate with the drive reduction gears to send back 12 v OR open to electrically shut off the motor power so as to not bust up the works....winds spring up waiting for alignment....but not over driving the plastic gears. DECOMPRESSION problem. You have 2 exhaust valves (depending on the year either 2 or 3 intake valves). The exhaust valve on the far side (away from the cam gear AND center located decompression cam/flyweights/springs) has 2 functions. When starting the flyweights are IN (spring tension) and the DC cam is rotated to push up a pin that rubs the rocker pad. The exhaust valve then opens slightly as long as the pin (5mm ish Dia.) is rubbing on the rocker pad. SINCE the valves are adjusted at TDC on compression stroke, there is a chance you might still be sitting on the pin and not know it-----wrong valve adjustment. The fix is to rotate past TDC then come back. You should hear and see the valve do its thing. You will see a deep stroke on both exhaust valves BUT only a slight opening from compression release function. Again there are 3 things found wrong in my past experience. 1. The pin had chipped out a groove in the slipper pad........no longer opened enough--the quick death method--chunks out at one time. 2. The decompression cam (in the center of the valve cam) has wear on the corner edge and gradually gives a shorter pin stroke length AKA, slow death. 3. Factory defective part. Hard to crank out of the crate. Found in BOTH Yam RHINO and HISUN Massimo. THE mistake IS identical----same supplier for both!!!! The fly weights are stamped main body and an extra "weight segment" welded to the main body. Extra weight was not aligned at weld station correctly and resulted the DC cam having reduced rotation....thus a die grinder fix. Q-LINK Youtube video posted on cam replacement. Entertaining on the chain/cam timing with CUT AWAY. HE! HE! HE! Give this post and video to the fella you are going to have a look see. Should give insight on what is happening.

Travis was on the right track. You have a strong running engine after you get it to start. The split vac hose was just a bump in the middle of the search, right? Carb/fuel problems will generate runability problems before and after starting. Bad connections, weak battery, parasitic drain, burned solenoid contacts, worn starter brushes reduce the power delivered and used to crank it over. Travis test of pulling spark plug...you said the motor spins over just fine with the spark plug removed......no load except friction and valve spring loading. You video was the TELL. Compression release is not doing it's thing. Totally random as it depends on where the motor stops (how far from the Compression stroke) AND how long the motor set since last crank/run......oil drain down and piston/rings get "DRY" lowering the compression. Fog cylinder or crank to splash/lube piston/rings....compression climbs back up. Physical example.....you want to push a small car on a level driveway into the garage. Problem is the rain shedding slope or a seam in the pours at the door. Would you push to the incline or bump and then STOP only to then try push it up the incline or over the seam??? NOPE, you would take a RUN at it. Same for the poor starter......no compression release.......grunt city per the video clip. The clip shows the "front" of engine with the intake valve cover (double lid) but not the exhaust. 3 valves? Maybe 4 valves? Should have a 2 into 1 exhaust header and 2 ea of the round screw off caps for adjusting the exhaust at the "rear" of the engine. Compression release works by SLIGHTLY opening for a SHORT time an exhaust valve during the compression stroke. Less grunt....motor gets a RUN at spinning over faster which will build compression more (less time for the slight EX valve to be open and leak off some of the fuel/air mix) to the point it is high enough to light off.... if the fuel/air mix is right. Exhaust valve adjustment is set between the rocker screw adjuster and the valve stem top face. This is important for the RUN function. The START function will be hindered if the valve is set too loose (wider gap) as it cannot open the valve slightly as much or not at all. Too tight will result leakage.....burnt valve seat/face when the whole motor warms up and EXPANDS as in the valve stem gets longer. ADJUST THE VALVES. FOR THE DOWN SIDE..................there are a couple of BAD things to go wrong.....one was a incorrectly machined flyweights (located on the camshaft gear) from factory and the other two are wear of the compression release "CAM" (located inside the valve camshaft) OR the ball/pin had worn a grove in the rocker/follower. ANY of these will result in NOT opening the EXHAUST SLIGHTY for a short DURATION=COMPRESSION RELEASE. ADJ valves and go from there. BE sure to get off the compression release section and only have the slipper pad adj screw to valve stem face....that that can also have wear problems. Lots to check here but that is what it is. The last problems require the rocker cover and cam to be pulled along with IF a pin/ball grove cut into the rocker/follower. The factory mistake can be fixed with a burr and die grinder (gets too deep for here right now of what and why details).

Sorry, I forgot to mention that a shorted Regulator can overheat and burn off the insulation on the stator winding coils....usually takes out every 1/3 pole piece around the clock as it is a 3 Phase system. Do a resistance test on the Y-Y-Y pigtail (regulator disconnected). R = .3 ohm Y to Y (3 times). If all 3 R readings are close, do a load test to mimic what the stator windings have to do in real life. Test with engine running----no load VOLTAGE will be 25-30 VAC at idle and up to 80 or so at 4000 RPM. LOAD TEST involves drawing current (POWER) off the 3 Y-Y stator pigtail leads. I like a 40 W incandescent bulb screwed into a pigtail socket available at electrical/hardware/HD/Lowe's etc. Touch any 2 of the stator output legs combinations (3X) and the bulb will glow at idle...30 VAC on a 120 VAC rated bulb. SLOWLY raise the engine RPM....brighter and brighter....that is good. On a hot 2 Phase system like H-D, you will be buying a new bulb if not careful.

You toasted the regulator.....NO CHARGE......motor running charge test voltage will be sitting at the battery's present terminal voltage......discharged say to 11.7v. The regulator is a shunt type------dumps EXCESS voltage, thus current to GND. The stator and the rectifier/regulator's output is "puny" compared to a light trucks RUNNING (100A area) alternator and 800 CCA battery. NEVER hook up to a smaller system EVEN right after pulling into location to give a jump as the host battery is still at 13.6Vv to 14.2V after shutting down engine. The poor regulator is trying to HOLD it's setpoint regulated output voltage by dumping the excess. POOF! The potting shatters when a F350 Diesel with 2 batteries and 120A alternator (running of course) is the host. Do a regulator diode test checking for F/B voltage on the 6 diodes from Y-Y-Y to R & B i.e. DIODE FUNCTION on digital meter to Y to R, Y to B.....times 3 for each alternator leg input...... .6v and OPEN. This does NOT test the SCR (switches) that do the actual dumping of excess current.....might show up in test as .0000001v instead of .6v. Killing off only 1 diode will result in only 1/3 the possible rated output. SO, you could be charging at idle with lights and engine electronics load BUT the winch motor will take more than the system can recover BETWEEN the adjustments to the snow plow height....slowly discharge to a no start condition.

B & S VANGUARD ignition problem. YES, same old magneto coil design from way back....no need for a battery to supply the coil current...the flywheel magnet rotating thru the mag coil "legs" is the power source. The mag coil has a low turns PRIMARY and a high turns HV output to the spark plug. 60's type lawnmowers used mechanical points (mounted to engine case I.e. GND) located under the flywheel that opened the primary coil circuit as the piston approached TDC-----8 deg BTDC. This same coil lead went to a condenser AND the throttle activated kill switch....before that a lever switch....before that, no electrical connection but a metal tab that was flipped over to short the top of the spark plug. Bottom line: KILL: the coil current is conducted shorted to GND. RUN: With the kill switch OFF.......the points do the same thing when they were closed.......BUT......OPEN (exactly timed by point gap and the ground/machined POINTS CAM flat spot on crank arm) to produce a spark from the mag coil HV output. ALSO, the flywheel magnet has to rotate under the mag coil "legs" or coil pole pieces AT the same exact time to generate a MAXIMUM magnetic field. The maximum magnetic field is what generates the NEG current pulse that flows to the CLOSED points. The desired spark timing is when the piston is at say 8 deg BTDC. The points are supposed to OPEN at this time in rotation for correct ign timing. NOTE: The flywheel key LOCKS the flywheel with the molded/cast magnet poles to the crank for it's share of the timing show. (sheared or 1/2 sheared flywheel KEY will be OFF TIME and therefore NO SPARK). The generated mag coil primary current PEAKS, the points now OPEN, and now the energy stored has to dump somewhere----somewhere being the HV coil windings-----SPARK. Vanguard is a 90 deg. V-twin...think of it as 2 singles scabbed together. Each cylinder has a Mag ignition coil. The magnet in the flywheel rotates under the respective coils with respective pistons at BTDC. IF cylinders were 180 deg. apart, there would be no need for the diode cable harness......a wasted spark system like the '70s era dual point in-line four cyl motorcycles AKA rice burners--H,Y,K, S. The timing is the 8 deg. BTDC with the wanted SPARK on the COMPRESSION stroke and the wasted spark at valve overlap...which does nothing because of the already burnt exhaust gasses are being pushed out. The electronic ignition module has an "electronic switch" that close/open(fire) for BOTH cylinders as they go thru the 8 deg. BTDC desired spark timing. The coils have to be ISOLATED from each other----DIODES......that pass the NEG pulse from CY 1 (thus the polarity requirement of cathode(band) facing the magneto coil primary) to the "POINTS" but NOT to the CYL 2 (which is BLOCKED by it's own diode----wrong polarity of pulse) coil that is not charges as of yet.......Diode failure will circumvent the sudden OPEN CIRCUIT req'd to transfer ALL the energy to the respective HV side of the coil. Results in no spark/wimpy spark/fouled plug/low power,,,woes. Making a jumper wire and connecting the magneto coils ONE AT A TIME will tell if both coils are good and that the ign module is giving the closed/open required to fire the coil AT TH E CORRECT TIME also.

Pull the connector to the fuel pump.......cannot dump loads of fuel then. DO the starter fluid runability test where you supply all the fuel by little squirts of the go juice on the air filter in the air box. Your unit is FI, therefore NO CHOKE. The original HISUN were carb models then changed to FI. The CHOKE function is now ELECTRONIC which is controlled by input signals from O2 sensor, Engine coolant temp thermistor, Mass air flow and intake air temp along with Throttle position sensor to determine engine load and thus the amount of fuel required for the demand. With the fuel pump disabled, you can then determine your next step.

Ech!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! That's a bummer........had some impossible to service units. Hang in there when getting around to do the tests.

DIODE LEAK......Can be just like a water well foot valve (one-way WATER valve) but instead of water leaking off, electrons (i.e. current) flows backwards thru the diode. They both pass in one (1) direction and restrict flow in the reverse direction. Get sand into a foot valve, water will leak back and loose prime at the well pump......slow leak. Over time the sand leak will cut the gasket resulting in a BIGGER leak. Now the diode......good one passes current (according to the band marking) in one direction WITH a small drop in voltage (0.60V)....thus 12.6v will be 12.0v after going thru the diode. The diode test meter function measures this voltage drop .6v in the PASS direction. The BLOCK direction of a GOOD diode will indicate the same as you never touched the leads (OPEN). Shorted will be way below .6v....like .030V....WOUNDED diode will have a value between open and short (like the grain of sand). Back to Vanguard......simple test of coils and electronic switch........pull the 2 into 1 B&S harness and make a jumper (NO DIODE) and connect to the cover terminal tie node (electronic points) with one end. The other will be put on the individual mag coil terminals (ONE AT A TIME). If coils are good, the respective cylinder will fire and the other dead. Move to the other mag coil lug and that one should run OK. They both generated a NEGATIVE current pulse (interrupted at the PEAK flux and "points" opening have no other leakage paths to GND. The mag coils and flywheel magnet poles are good AND the electronic points are opening at the right time. Now, you have only one electronic switch so the diodes have to isolate PASS/BLOCK WHEN required per cylinder. It might be easier to just buy a new harness as the parts and labor build couldn't be more than $2.00 max.....single one up build....not in qty. purchase prices. Hope this helps this time. Checked out UTUBE....there is a clip showing the harness....no testing, just replacement. check it out.....a picture is worth a 1000 words.

I'll try again........4 stroke V-twin with probably a 90 deg angle between cylinders. 2 rotations of the crankshaft for INTAKE, COMPRESSION, POWER, and EXHAUST. Cam runs at 1/2 speed (2 crank rotations per single rotation of the cam).......therefore, you will have the magnet rotate under the dual mag coils TWICE for each cycle. Timing of the SPARK is req'd around 8 deg BTDC on the COMPRESSION stroke. A single cylinder engine has 1 mag coil and 1 set of "points" (mechanical or electronic switch). The Vanguard has 2 mag coils BUT only 1 electronic switch....that opens and closes in time with 8 deg BTDC of BOTH respective cylinders. The mag coil(s) are "CHARGED" one at a time spaced 90 deg apart WHEN the magnet poles molded into the flywheel pass under the mag coil lamination "legs". The Primary winding has the one end connected to GND. The other end is the side lug going to the points. The magnetic CHARGING causes a NEG (-) current pulse....same as the OLD point system that has to be suddenly stopped by the points OPENING. Think of water hammer when shutting of a sink valve TOO fast. The high tension of the mag coil will pop out 7KV or more when the energy has no where to go when the points open. Testing would be simpler if there were 2 points or electronic switches for the 2 mag coils. COSTS MONEY FOR THE SENSE AND DRIVER/SWITCH COMPONENTS. The combo mag coil primary circuit harness is a 2 into 1 BUT with BLOCKING DIODES. Without the diodes (or a faulty diode) the mag coil ( - ) current pulses will feed each other coil primary resulting in a wimpy weak spark in time for 1 cyl and out of time for the other........BOTH ways as the flywheel rotates under the OTHER mag coil legs. The pair of 10 cent 1N4006 diodes is really a cost savings over having a dual electronic switch ign module. Diode is one-way current valve.....they are both placed cathode to the coil primary spade lug connection. When working, each diode will PASS it's respective ( - ) coil current spike to the electronic switch.........BUT cannot flow backwards (blocked) to the non-energized mag coil and steal the spark generating energy. FAULT results in dual wimpy sparks...1 in time and 1 out of time spark from the other cyl mag coil. The kill wire also goes to the cover connector like before as was on small lawn mowers for the STOP position of the throttle lever. Test the diodes...they may test good and then fail later...that is the way they are with mechanical vibration on the leads (breaks the internal termination to pellet). Easier this time?????

HI there.....not to bust your bubble BUT your problem of weak spark/good spark MIGHT come back when you need it the most. Vanguard is a v-twin with a magnet section molded into the flywheel that goes under the respective mag coil for each cylinder. Go back to the old days when a single cylinder engine was "the" B & S engine. Remember before the electronic mag ign coils??? Under the flywheel and Al lid was a set of points and condenser. The little fiber "points pushrod" that rubbed on a flat spot on the crankshaft arm that opened the points to fire the coil????? The throttle cable "kill switch" that had to be adjusted correctly or it would short the mag coil/points/condenser lead wire to Gnd??? The magnets in the flywheel had to be timed very close to TDC to GENERATE A PEAK MAGNETIC FLUX in the mag coil when the piston came upon TDC on compression stroke..... and......of course the overlap stroke that was wasted. A sheared flywheel key would be a no start/run condition??? Oh, those were the simple days. BUT WAIT, magneto/ignition coil circuit/"points" electronics did NOT change......just evolved into electronic switches to replace the high maintenance points. The low voltage wire from both coils still "need" points......electronic points that is. BUT, on the Vanguard V-twin, they tie together and come out as a single wire to the IGN terminal mounted on the cover. Simple little harness....3 lugs....and a DIODE in each coil leg. The electronic points will "OPEN" at the correct time for BOTH cylinders.......but there is only 1 magnet in the flywheel and 2 mag coils (1 each cylinder). Therefore, only one mag coil can be "charged" at a time (when the flywheel magnet rotates under each cylinder's respective coil)....Sorta the same idea behind car engines up to the late 60's (points cam, external ign coil, and rotor/distributor).....selecting which cylinder gets the spark as needed. Problem is, EACH of the coils primary currents need to be ISOLATED during it's time/turn for a spark output to get the FULL or max current then cut OFF quickly. DIODES to the rescue!!! DIODES-----one-way electrical valves----current only flows thru diode in one direction Diode polarity(s) in the harness is Cathode (silver band on black plastic body) to the mag coil terminal. Both Anodes (the opposite non band end) tie together and go to the "electronic points" cover connector. The coil current is a NEG pulse generated by the rotating magnet poles that gets cut off (OPEN by the electronic points)----like the old days----The mag coil has to be OVER the magnet poles on the flywheel to generate the "energy"......actually a magnetic field in the coil and laminations. Thus the coil can only fire when rotated over the flywheel magnet poles AND when the "points switch" OPEN. There is only one flywheel magnet section. Thus,the mag coils are energized at different times (V angle) and a NEGATIVE current pulse flows from each mag coil lug AT IT's CHARGING TIME.....thru the DIODE.....then to the electronic switch cover connection.....a CLOSED electronic switch that OPENS at peak for the spark at the correct timing(s). DIODE FAILURE MODES: Blown open....no spark on dead section coil. Other coil has spark. SHORTS......will have spark at both coils BUT wispy weak---thus fouled plugs. WHY? Well, the system has to mimic a mechanical set of points......CLOSED for PEAK coil current when mag coil is over magnet poles....then......OPEN at the desired ign timing point say 8 deg BTDC.....Primary mag coil current at MAX then a sudden break in current (magnetic field energy collapses across the HI side coil winding=high voltage spark on spark plug lead). With a harness diode shorted, the sudden "point open circuit" has the primary winding of the OTHER coil drawing current (NO ISOLATION or back feed) that "drains" the energy slowly (wispy weak)instead of a rapid coil current cut off (hot spark). HARNESS DIODE TEST: Pull the covers to expose the ign coils and the simple 3 lug harness. METER ALERT!!!! Digital meter with DIODE test function req'd. Si diodes have a front to back resistance of very LOW R in one direction to HIGH R...>500K or "open circuit". Diode Test function runs about 1 ma DC thru tested diode. GOOD DIODE.......Meter will indicate .6 in forward [red (+) to Anode (non band end)] and black (-) to band end. Reverse leads on diode under test....should show same as before making the connection (OPEN). SHORTED DIODE.......0 or very low .0002 number BOTH DIRECTIONS. OPEN DIODE.......HI resistance both ways....same reading on meter with leads in open air. I like to then go from DIODE FUNCTION to 500K Ohm scale, wet fingers and hold meter leads to diode leads with wet fingers of both hands....should see around 200K ohm...then open one set of fingers and remove your body resistance from the circuit....just a simple test to make sure the meter is working.....should show open. FINAL WORD ELECTRONIC PARTS CAN WORK AND THEN FAIL ONLY TO COME BACK AGAIN AND WORK. These are the worst to T/S and of course NEVER FAIL when the customer is trying to show how it fails...been there?????

Hello again. I jumped into 3 problems I have seen in the past. Mice love the filter material....a sitting machine is a welcome mat. A clogged filter or nest in the intake is the same as a B&S engine turned over and the air filter flooded with engine oil...cannot draw enough air and results in a "choked" carb condition. Remove the throttle body intake boot (the rubber collar going to the air box) and avoid getting dirt into the intake. This removes all air flow restrictions. The reason for a new spark plug is trouble shooting/testing....need a clean plug for the test run. IF it runs OK with the boot removed, problem is in the intake circuit. The old fouled plug won't run right and negate any testing done. The run time is just long enough to see if it works.....BUT not too long as to load it up like the old plug. STILL NO WORK....next line below. COMPRESSION and SPARK. Pull plug and put finger over the spark plug threaded head hole....attempt to hold in any pressure....WOT (gas pedal to floor) and unrestricted intake air (takes air to make AIR), CRANK OVER ENGINE....IF finger blows off with a POP (note might BURN if you seal it too tightly because of the air burst JET) you have enough compression. Cheap and dirty compression test without tester. IF GOOD, skip next section below. NOTE: low compression and/or a weak spark will mimic a RICH fuel mixture....sooty black plug. REASON....fuel is not burned completely by misfires....builds up on plug insulator (wet plug) and then foul. LOW COMPRESSION.......diesel engines fire (without spark) on HIGH compression of fuel/air mix. Gas engines only require say 120 PSI compression of the fuel air mix. Low compression causes: timing chain jumped (valve timing off), valve adjustment too tight, burnt exhaust valve/seat, rings work or stuck in piston grooves. SPARK....spin engine over and hold sparkplug to any metal on engine. Should have nice fat hot spark and not a wispy wimp. Slowly lift the spark plug thread body away from the engine....should jump a good 1/4 inch gap and then try to find a better path to gnd....that being YOU. Follow safe methods. NOW an easy check of the timing of the spark. Finger over hole as before but LIGHTLY, no throttle required this time, crank engine and observe spark.......should fire on every rotation of the engine (waste spark system) which will be twice (exhaust and compression strokes). You are looking for a spark timed to the compression POP/spit on your finger. IF a question of timing...use a timing light BUT you have to remove a cover on pass side of engine to get to crank rotating member. I have used a timing light looking thru an INTAKE valve cover lid but this can be confusing because you will see two (2) flashed images....cam runs at half speed so you will see valve closed (COMPRESSION) and a slight blur/shift from overlap where the intake valve starts to open at the EXHAUST to INTAKE stroke time (the wasted spark). You had one good suggestion about go juice (starting fluid). Find fuel tank under pass seat.....round "plug/cover" for fuel pump. Note the 4 wire connector which is the fuel pump supply +12Vdc and Gnd and the fuel level sending unit. Remove clip and disconnect the 4 wires.....now no fuel pump to 40 PSI...no fuel at the injector after initial residual pressure drop...no chance to foul NEW plug now. Crank over engine and it might sputter from residual fuel pressure then just plain crank and no run. Feed the go juice in spurts......to filter (intake duct tube all connected---air box lid OFF). REASON: If INTAKE valve is OPEN slightly say due to being adjusted too tight or jumped cam timing, you will get a flash fire back thru throttle body...Risky shooting directly into the throttle body. DOES the engine run of the burst? and then die after it sucks go juice out of filter. Try several times and note engine runability. Crank again and give another shot burst to get running....NOW, you give bursts to keep it running after trailing off and note engine run quality. IF you can simulate a CARB system (remember the injectors and shooting blanks and the throttle body is now just a carb butterfly valve and YOU are the fuel metering jets and passages), your problem is the fuel metering by the Delphi ECM. The DELPHI ECM module can fail....seen only one bad on B&S large engine (wounded but NOT dead that did screw up fuel delivery) but very rare......most fueling problems are due to the multiple inputs to the module. some were caused by other repair shops sloppy work, wiring harness problems, mice love wire insulation, O2 sensor failure, and so on. Digest these LOW tech (no scope or meters req'd) testing ideas and get back.....BEN P.S. Old is only a state of mind....just don't do stupid stuff because your body doesn't heal as easily. Give you a hint---loser on first draft lottery....do the math.

You are running rich as noted by the fouled spark plug. Multiple things to try.....you said it was at a repair shop for 5 months???and then came back rough running. Remove throttle body intake boot from air filter...checking if a critter moved in and choked off the air intake supply. Don't drive/run around to get dust into the intake. Start with a new NGK plug. Next item to check, disconnect the connector to the O2 sensor. With it missing the signal, the Delphi ign module will default to a almost limp mode. A bad O2 sensor will run ratty (bad signal) but disconnected.....computer will try to run on a good map. Another thing is the thermistor mounted in the head.......cold temp will have a high resistance (to ground---the head) and hot reading will be a low resistance. The voltage source is the ECM (5 volt) with the changing resistance to ground (thus the changing voltage signal) maps the fuel pulse width----think of a carb choke gagging in extra fuel on cold startup and run......Just like a throttle position will have a voltage range from .6v at idle to 4.5v at WOT....wide open throttle......voltage cold will be close to 5v and warm 3v and hot 1v as a general rule of thumb. IF the wire is open from the ECU to the thermistor, the ECU will see 5 v and think it is at the south pole------COLD=extra fuel. Check voltage at the thermistor...open wire will indicate 0v but 5v at the ECU pin=extra fuel. Happy hunting.

TPS------most are set to .5Vdc for idle. CHECK....engine not running but KEY ON....should have Gnd, +5Vdc, AND analog signal that varies from +.5V (on throttle idle stop) to +4.5V at WOT....should move SMOOTHLY going up and also going down...open and close slowly so the digital meter has time to respond. If the throttle body manual idle speed has been "adjusted", this will throw off the TPS curve. The screw is usually painted at the assy plant for a certain airflow. NOT TO BE CHANGED. Idle Air Control valve controls the idle speed via the Delphi ECM. A problem with the O2 sensor can cause problems.......Disconnecting allows the ECM to revert back to "limp home" setting from internal map. The Mass air flow/intake air temp sensor also will mess up the settings. If it took a swim, the sensor (air flow) will have dirt problems. The temp part is just a thermistor bead on 2 leads.....resistance changes with temp.

Peak voltage of the pulse output of pick-up coils is related to the magnetic field strength AND rotational N-S-N-S-N etc. speed (rate of change in magnetic field. you can check the PEAK output with a scope or special testers OR a simple SNAP-ON peak voltage adapter that plugs into a digital meter. First guess (assume the new crank sensor/pick up coil was good and no corroded wiring to ECM) is too wide of an air gap between the coil face and the flywheel tab (magnet is internal to the coil). With a wide gap, the output will be too low to trigger the ign at low RPM but the output will be high enough at a higher RPM. TEST TRICK........QUICK SUB OF CPS/PICK UP COIL. Create a pick up coil signal to test the ignition section but not needing to turn over the engine. Pull sparkplug and mount in boot again, have known good pick up say from a chino scooter connected for a FIRE signal, KEY ON, and then take a small wrench (iron) and stroke the pole face and mounting metal tabs.........make and break the magnetic field flux "conduction". Should se a nice spark

Start at the battery + post.......this node will have 3 wires----2 heavy and 1 lighter Ga. Heavy(s) go to starter solenoid and winch contactor (assuming your unit has factory or owner installed wench). The lighter red wire goes to the 30A MAIN fuse and then to a 4 pin connecter. I assume your regulator is mounted under the hood also...frame rail high drivers side.....which go into the harness gathering up multiple pigtails and gets fatter as it heads to the passenger side. Your problem is inside the loom and less than 6' of run. The problem with the RED wire is a blind splice inside the loom with a CRIMP JOINT.....as the +12V ALWAYS HOT goes to the IGN SW also as a branch circuit. Now to rain on your parade-------the crimp is a BAD high resistance connection------it can turn into a meltdown like the regulator connector....BUT A BURN WILL TAKE OUT OTHER WIRES IN THE HARNESS.....Razor blade......careful cuts of the loom sheath......find the node (crimp tie in or "breakout---in cable slang")....strip back the insulation for both wires....scrape/sand/brass brush the wire strands.....I like to then do a twist loop of the branch wire over the main run wire-----solder (rosin core) 60/40 LEAD still the best solder to use if you have old stock. BUT.....lets determine that the RED wire has a problem. Test light stabber type (I used actually 2 of them----one with the standard wimpy light bulb AND one with a Chevy dome light round glass tube bulb----lots of current draw and gets handle hot with use. Connect clamp to - Battery post. Stab the + post......light burns bright. Next stab the MAIN fuse both sides.....should be bright. Next go to the 4 pin connector...bright? Now jump to the RED wire on the Regulator. Should be bright------IF NOT you lost it in the harness. TRICK TIME: Called the shake test.....leave the stabber on the Regulator RED wire and then thump the harness heading back to the battery box on passenger side......light flicker means you are on top of the splice or close. Cut the wire ties (holding the harness) and then FLEX the harness looking at the test light bulb brightness/dim/flicker. BONUS TIPS Rear diff-----VSS is the plug (unplug the connector and then screw out the sensor---don't wind up the leads). Check the fluid level.....IF not serviced correctly most are low from factory.... monkey shops and on line buys skip this one. No need to explain the gore here. Air in cooling system-------you get a hot engine/cold radiator overheat condition.....means you warp head/jug/head gasket leak. Raise the front of SxS at least a foot (12") and fill radiator neck 50/50 mix. Puke jug hint later. Locate the head bleed screw where you would think the thermostat would be (nope---down low by the stator/flywheel) Should be a 8mm hex head.....this bolt is easy to twist off so don't go heavy on the Al sealing washer. CRACK open with engine running......if air in head----bubbles then solid antifreeze. Milk the rubber hoses low in passenger side to BURP-----watch filler neck-----will rise and fall. RUN engine and feel the head (usually the hottest spot) or use a IR temp guy (AKA COVID-19 TESTER). An AIR BLOCK will keep the coolant from flowing. Follow the head coolant connection and check for the AL pipe also getting warmer....Heat should make it to the radiator also.......BURP.......warmer antifreeze will overflow.......IF GOOD...STOP.....ready to purge the puke jug......HINT....follow the hose from filler next to the jug....these hoses like to split. FILL to COLD line plus an extra 50CC for the hose volume. MOTOR OFF......connect the hose back to filler neck and slightly pressurize the jug......object is to fill the hose and remove air bubbles....install radiator cap while slowly "filling the neck".....RUN engine checking temp everywhere------head------Al pipes----radiator top and bottom. Should see a few Deg temp difference thru the system. ELECTRIC COOLING FAN.......common problems No =12V at fan... hot but not running)-------one of 3 problems. Temp switch failure (bottom of radiator).......connector in mud/crust with a bad connection to the 2 lugs..........harness failure of KEY ON +12V open to the thermo switch. The thermo sensor on the head is for the dash. Have KEY ON, test light clip to GND and stab the radiator thermo switch lugs.....one will light (red tracer?) coolant cool....both will light with radiator HOT......Fan should run. TO TEST the circuit for T/S for fault.....a HEAVY paper clip opened up to make a horseshoe shaped jumper wire......KEY ON----jump switch.....fan should run. This means that if the radiator gets hot enough to toggle the thermo switch, the fan will work.

did the above REPLY on load testing the stator make it??????

Be careful with meter readings. Short the test leads together.....most meters will not show 0 ohms. If you start out at say .3 and you have .2 in the circuit, meter will give .5 ohm. Some meters start out NEGATIVE and then subtract from the total like -.2 +.2 will indicate a dead short of 0 ohms. I use a LCR bridge meter with 4 leads to measure low resistances. The real tell is using the L inductance scale. Leg to leg to leg value should be very close (with the following condition---------the flywheel has multiple (of 3 again) magnets glued to the inside of the "drum". The L value will change with the location of the N-S gaps as engine is slowly rotated. Go for the MAX value). If the windings are shorted turns (not burned open-----shorts in the layers of wire build)------the inductance L will be lower by a factor of 10 or greater leg to leg. Perform an at idle OUTPUT test with a 40W to 60W light bulb load. The regulator is unplugged from stator.....the bulb is connected to the stators WHT WHT WHT leads with 3 tests. The bulb will be dimmer when connected to a damaged winding (set/phase pairs). Beauty of this test it is a current draw and not just an unloaded meter voltage reading. Think of a weak battery that handles the headlights of but fails on the 200A + starter draw. BEN

Your stator is a 3 phase "Y" output. The winding "LEGS" are the 3 white wires......call/label them A B C. Look at a parts list to see the stator is a laminated steel ring with a multiple of 3 poles---like 12 or 15. The windings are connected BUT NOT TIED TO GROUND at the starts----thus the schematic Y look. Each leg is wound in series on every 3rd pole and act like stacking a string of batteries in a 5 cell flashlight....except the poles produce AC. The AC output is measured from white to white, white to white, white to white.........A-B, B-C, and C-A. Idle voltage is around 20 VAC leg to leg (3 times). Higher RPM will produce on some systems around 80 VAC.....CAREFULL HERE. The resistance check (here again leg to leg) is thru 2 sets of pole coils.....IN one of the whites----to the center tie point----OUT to the 2 other white wires. Measure A-B, B-C, C-A...... .2 to .3 ohms. Also check for any path to GND....high M ohm scale should be infinite as in open circuit. A 120V/40W light bulb will glow when connected A-B, etc. Some systems will blow the bulb if motor Rs too high Your problem with the melted connector plug was corrosion. The connection resistance will heat up the terminals and with enough heat, melt the nylon connector body......this goes on for a while THEN it goes BAD when the terminals touch.....shorting out the STATOR windings. If opened up, you will find the varnish burned off 2/3 of the 2 legs effected. The coils short down and the resistance check will be sub .1 ohm. Output voltage test will NOT be equal leg to leg also. As an added bonus, the stator will cook off with additional engine run time. I found that the voltage REG will still be good.....burned terminals and all.....most of the time......but die later. The RED wire goes to the + battery terminal. Black goes to GND....- BATTERY POST. Test with a test light to ensure a good connection as in probe to REGULATOR RED wire and clamp to GND AND probe to REGULATOR BLACK wire AND CLAMP TO BATTERY + POST. Voltmeter will lie to you and say a good connection. An example would be BLK test lead to GND......lick finger and touch RED meter lead AND use another finger to touch the + battery terminal.....meter will read 10 to 12 VDC...says you have a good 12V....NOT. BONUS HINT: finding the correct connector and terminals to match the REGULATOR might be tough. FIX is to use a aftermarket RICK's regulator that has pigtails.......cut and strip both stator and regulator wires.....match R and B......the 3 ph whites don't matter...totally random mix when harness was produced and regulator has 3 identical input circuits. TEST STATOR FIRST FOR DAMAGE/FAULTS.

FUEL SYSTEM Your unit is before FI and in-tank 40 PSI electric fuel pump. The diaphragm fuel pump/pressure regulation mini tank set up has some issues. The supplied diagram and routing is good. The pressure required for the carb to accept fuel.....float valve is a nominal 3-4 PSI. The height of the mini tank fuel level above the carb bowl fuel level only gives 1 to 1.5 PSI. This is the pressure regulation of the set up. PROBLEM...."vertical height" difference can be almost nothing when climbing up out of a steep sided creek bank or hill.....runs out of fuel when the demand is the highest.....the level in the mini tank is still the same, it is just the mini tank rotation downward....lower....as the UTV front rises. I have moved the tank up higher.....less lean out popping but looks stupid mounted to the roll cage bar. The Tee at the carb will let most of the fuel just return to the main tank....path of least resistance. That has to go. Now for the pump pressure over powering the carb's float valve....if you have a ring dent in the needle's rubber tip.....the mini tank clears that up. Go back to the mini tank and see if you can live with the above mentioned flaw. Check valve-----foot valve in a water well system-----I found that only one in tank pickup (gumdrop) will flow at the slight draw the fuel pump generates to crack open the check valve. It also had a fine mesh screen to keep grass, weed seeds, etc. out of the fuel intake. Alternate fix.......low pressure adjustable ELECTRIC FUEL PUMP from auto stores O'Reilly's. Connect direct to carb hose barb. With a remote switch, you can drain down carb before shut down AND then refill with "fresh gasoline" for easy starting. Heat soak floods intake (expansion) and as an added bonus, the fuel looses it's POP. used this trick on multiple golf carts that were hard to start. SHIFT PROBLEM. looking at the supplied image, notice the shift linkage adjustable rod....REMOVE one end coupling. The lever bracket attached to the motor (actually the shift cam shaft) can now be pushed/pulled to find the shift point detents. See if the dash gear selected LED matches when pushed into a gear.......checking the shift indicator switch. NOTE: the hard shift-grinding gears can happen if the carb idle speed is set TOO HIGH.....wet clutch is starting to engage. You should have the gears at detent (possible bent shift forks if not)....NOW sync the shift lever to the detents...connect the rod back to bracket at motor. ROD THE RIGHT LENGTH???? You found the adjustments (L and R threads and lock nuts)...find the correct length. SHIFT LEVER moved between RNHL....ALL HIT CORRECTLY???? You can have one end but not the other NOW for the BAD NEWS.....you will find out that you can get one end BUT not the other....ADJUST to the OTHER and the former now does NOT work..............................ANALYSIS of what is WRONG......Shifter lever does NOT have enough travel to get BOTH ends to work. SIMPLE FIX....The shift lever end is TOO SHORT....AND/OR....the motor shift bracket is TOO LONG. Easy to fix......REMOVE the motor shift bracket.....there is a dog leg bend(offset) between the D hole and the ball end. take the bracket and lay it down in bench with the "ball" up. You need to save the dog leg offset SO go closer to the D hole (wider here about 25mm---1"). Take a center punch and mark (dot) close to the bend AND close to the D hole (but not too close for mounting screw and washer)...the punch marks are for the correct reassy of halves AFTER you cut the bracket IN HALF across the wide area. 1/8" to 3/16" with cutoff wheel is removed and then use a wire welder to make it WHOLE again----JUST SHORTER. Bevel the edges, have punch marks on same side as it was before cutting, tack to have a FLAT bracket again, burn it in and trim excess. With the shorter arm on the motor end, the same adjustable linkage rod travel will ROTATE the bracket/shift cam more.......READJUST the rod and should have enough rotation for both ends of gear selection.

T/S to the basics required for motor to run SPARK at CORRECT TIME FUEL/AIR MIX COMPRESSION SPARK PLUG------pull spark plug.....check plug condition at electrode.....looking for WET, SOOTY BLACK---all bad. Want a dark TAN electrode insulator color. A FOULED plug or internal damage will not let the spark jump the electrode gap....NO RUN. SPARK TEST.....plug out......You want a NEW plug if any question of condition.....this will create an ignition source (spark) for any fuel spills, loaded cylinder what blows a spray of raw gas---very exciting, etc. Pull the ignition coil low side primary connector. Spin over engine and check for blowing fuel. If mess, blow off fuel with air hose and blow into the spark plug hole also. Vent out fumes from shop. Actual spark test-----reconnect the ignition coil connector. Put known good spark plug in cap and place plug on metal frame or engine case. Spin over the motor....2 things happen......hiss of air thru spark plug hole AND the snap of the spark arc. Now put finger over the spark plug hole like using a thumb on a garden hose. on the COMPRESSION stroke, the escaping air will "blow off" your finger if engine mechanicals solid. Should have a nice POP. The spark should fire at this time......about 8-12 Deg. BEFORE the piston hits TDC on Compression stroke. If you have the above conditions go to next test. COMPRESSION-----finger pop test is a quick and dirty check. It takes air to make air....open the throttle to allow air into the intake unrestricted. Use of a compression tester is needed to get a hard number like 120 PSI or better. Not a testers are created equal......use one that has the valve core in the spark plug hole screw in end. use of a hose extension will lower the compression value indicated. Also engines with auto compression releases will be lower also. use manual spec'd value in these cases. Other causes for low compression....valve adjustment clearance too tight. Carbon under valve face/seat. Burnt exhaust valve. "birds beak" plasma gas jet erosion of valve face. Worn out cyl/rings. Cam chain jumped timing or broke (mechanical problems) FUEL/AIR MIX---------For the problem of run/no run depending throttle setting: CARB....shut off fuel to carb......drain bowl......you will manually supply the fuel later THROTTLE BODY......you are FI so disconnect the fuel pump connecter UNDER the Pass side seat. Lift out the seat.....fuel tank is right there.....remove clip and then part the connector halves....result on new fuel introduced for testing. FUEL TEST--------everything from above reinstalled, spin over engine...should NOT run but might if raw gas is in air box. here is where you supply the fuel to the air intake....starter fluid short bursts.....if engine fires and runs then dies after a few seconds after the fluid runs out, give another burst.....runs....dies...do again but then try to time the bursts to keep running for at least 10 seconds. If it works with the starter fluid boost.....you have a fuel problem. The problem could be any of the following: Fuel delivery supplier mixed DIESEL and GASOLINE in tank Corn gas has too much water added and syrup won't burn----phase separation Water in fuel tank....rain or flood water or pressure wash tank vent. Low fuel pump pressure-----40 to 45 PSI normal for these FI systems Fuel filter got water in it or sediment clogged ANY CONDITION FOR FUEL CONTAMINATION......start with draining the fuel tank....have to go thru the fuel pump lid and lock ring which may be too much or more than you want to tackle. Basically the tank drained, fuel pump drained, lines drained between fuel pump and injector. REFILL with new gas NON-CORN (recreational gas) is best to run anyways for these machines. Cycle pump to fill lines all the way to the injector body....pull injector and crank engine (KILL SPARK) and look as spray mist as injector fills and then fires....bad spray sometimes means a new injector after everything else is cleaned up. Try above----post back findings

the small hose from the carb body goes into the bowl space-----atmospheric vent. they will get bugs nests or dirt, water, and then reduces the fuel flow thru the FUEL JETS. There are AIR JETS (sometimes well hidden beneath the diaphragm porting on CV carbs) that draw air (clean air box air) into a junction within the carb body cavities TO the MAIN and IDLE fuel jets extending (aspiration) into the bowl fuel. these "air flows" are separate from the full bore and throttle plate stream of intake air. the fuel is effectively drawn into the bore with an entrance at the main jet brass nozzle and a small hole(s) south of the throttle plate or slide (depends on carb type). simple way to think about the vent......you have to let air in when sucking the soda out of a bottle. same goes for the fuel tank has to be vented....be it a simple hole in cap of a full blown EVAP system.....air in for fuel drawn off. some machines run this hose (usually bigger because air has flow resistance) to a frame cavity.....think mice, mud dobbers, backwater floating trash etc. you can change the carb 50 times...still a dog in the pile. you might want to raise the end to a protected area but still have the loop end DOWN to avoid water flowing in. The bigger hose from the crankcase PCV feeds oil vapor and blow by fumes to be reburned by routing into the airbox....thus the oil mess on filter. EVAP canister gas tank fumes are also gated back to be reburned......that is why overflow carb----gassy oil will also cook off and screw up the F/A mixture. Might as well cover the 3rd fuel/air circuit on carbs that DO NOT have a choke butterfly......that gags extra fuel from main and idle jets. these will have a second cable to carb or a linkage on multi carb setups. the basic function is to open an air passage (calibrated drilled hole) by lifting a slide (6mm dia or so.) off a seat and also pull the extended pin out of the fuel jets passage.....have a flow of air sucking metered fuel into a larger hole directly in to the side of the bore throat. mis routing of the choke cable can open the enrichment circuit (choke) when turning handlebars and then be fine on straights.......H way back bad for this....plug a day habit!!!!!! That's the short of it. chow